I'm not sure if you were talking about my post, but I'll act as if you were.
Cost really isn't an issue here. You can get quite cheap ($7) Aduino clones that work just fine. Sure, you can save $2 per project, but at the expense of additional work and managing wires and components. It's a whole production. My requirement was to run indefinitely on a small battery, and to do that you need to strip out all the unnecessary "fat". There are many places on the internet showing you how to do this.
If power weren't an issue, I would have used an Arduino production board.
You're right, the code *is* the same. I wrote it all entirely for the Atmel 328 microcontroller. Looking at my picture above you can see that I've done exactly what this website shows you. On top of that I've simply added whatever components I needed and controlled them from the microcontroller's I/O pins.
Further, I used this guy's tutorial to put the microcontroller into super-low-power sleep state.
I don't have any wiring diagrams, but anyone attempting a project like this should be able to completely understand these fairly simple electronic components. If you have any questions you can email me at [email protected], where "xyz" is actually "wavecable". I don't want to spell out the email address so it won't get harvested by spammers.
